Control apparatus and control method of on-vehicle electronic equipment

Abstract

An apparatus and a method that includes a program execution monitoring dedicated circuit connected to a CPU of a control apparatus of an on-vehicle electronic equipment that includes an execution time monitoring timer circuit ( 111 ), an execution sequence monitoring comparison circuit ( 113 ), a setting register ( 115 ), an attached circuit ( 117 ), perform monitoring of an execution sequence of a task executed by a control program of the on-vehicle electronic equipment and/or an execution time of the task executed by the control program, and enabled to continue the control of the on-vehicle electronic equipment such as an electric power steering apparatus by performing an alternative processing in the case of detecting an abnormality in the execution sequence and/or the execution time.

The invention claimed is: 
     
       1. A control apparatus of electric power steering that a program execution monitoring dedicated circuit for monitoring an execution sequence and an execution time of a task executed by a control program of said an electric power steering is mounted on said control apparatus;
 wherein said program execution monitoring dedicated circuit is provided with at least an execution sequence monitoring comparison circuit, an execution time monitoring timer circuit and a setting register, 
 wherein monitoring of said execution sequence of said task is performed by comparing respective head addresses of a plurality of tasks that are preliminarily registered in said setting register with a head address in command fetch by means of said execution sequence monitoring comparison circuit, 
 wherein monitoring of said execution time is performed by comparing an execution time of said each task with an execution time threshold preliminarily set for every task by means of said execution time monitoring timer circuit, and 
 wherein in a case that said execution sequence of said task is different from a sequence preliminarily set or/and in a case that said execution time of said task exceeds a threshold preliminarily set, said program execution monitoring dedicated circuit continues a steering assist by outputting a signal preliminarily set and performing an alternative processing. 
 
     
     
       2. The control apparatus of electric power steering according to  claim 1 ,
 wherein said alternative processing 
 performs any one processing of a processing that performs a task corresponding to a regular sequence, a processing that performs another task having a short execution time and preliminarily set, a processing that redoes from a previous task in which an abnormality occurs, or, a processing that redoes a whole process being executed depending on importance of a process and so on in said case that said execution sequence of said task is different from said sequence preliminarily set, and 
 performs a processing preliminarily set for every task as substitute for said task in said case that said execution time of said task exceeds said threshold preliminarily set, 
 wherein said alternative processing is performed by an interruption to a CPU, and after said interruption by said alternative processing is passed through, a control of said electric power steering can be continued by shifting to execution monitoring of said control program again. 
 
     
     
       3. The control apparatus of electric power steering according to  claim 1 , wherein an on-vehicle MCU is equipped with said program execution monitoring dedicated circuit. 
     
     
       4. The control apparatus of electric power steering according to  claim 2 , wherein an on-vehicle MCU is equipped with said program execution monitoring dedicated circuit. 
     
     
       5. A control method of electric power steering that uses a program execution monitoring dedicated circuit for monitoring an execution sequence and an execution time of a task executed by a control program of an electric power steering to monitor an execution state of said control program of said electric power steering,
 wherein said program execution monitoring dedicated circuit is provided with at least an execution sequence monitoring comparison circuit, an execution time monitoring timer circuit and a setting register, 
 wherein monitoring of said execution sequence of said task is performed by comparing respective head addresses of a plurality of tasks that are preliminarily registered in said setting register with a head address in command fetch by means of said execution sequence monitoring comparison circuit, 
 wherein monitoring of said execution time is performed by comparing an execution time of said each task with an execution time threshold preliminarily set for every task by means of said execution time monitoring timer circuit, and 
 wherein in a case that said execution sequence of said task is different from a sequence preliminarily set or/and in a case that said execution time of said task exceeds a threshold preliminarily set, said program execution monitoring dedicated circuit continues a steering assist by outputting a signal preliminarily set and performing an alternative processing. 
 
     
     
       6. The control method of electric power steering according to  claim 5 ,
 wherein said alternative processing 
 performs any one processing of a processing that performs a task corresponding to a regular sequence, a processing that performs another task having a short execution time and preliminarily set, a processing that redoes from a previous task in which an abnormality occurs, or, a processing that redoes a whole process being executed depending on importance of a process and so on in said case that said execution sequence of said task is different from said sequence preliminarily set, and 
 performs a processing preliminarily set for every task as substitute for said task in said case that said execution time of said task exceeds said threshold preliminarily set, 
 wherein said alternative processing is performed by an interruption to a CPU, and after said interruption by said alternative processing is passed through, a control of said electric power steering can be continued by shifting to execution monitoring of said control program again. 
 
     
     
       7. The control method of electric power steering according to  claim 5 , wherein an on-vehicle MCU is equipped with said program execution monitoring dedicated circuit. 
     
     
       8. The control method of electric power steering according to  claim 6 , wherein an on-vehicle MCU is equipped with said program execution monitoring dedicated circuit.